"Based on that, looks to me like recovered part is in full nose down position. Am I missing something? "
Are you overestimating the amount of travel the ballnut moves? I see about 6~8 inches of chrome above the ballnut (wild guess, not knowing the diameter of the screw). Subtract 1 inch to get the start point of 0.25 units. There is 21.51 inches of travel from here (to reach 12.8 units). That is 1.7 inches per unit. So, 5~7 inches (say 6) is 3.5 units from 0.25 units = 3.75 units. Neutral is 2 units, so 1.75 units nose up. I need a fellow engineer to check my numbers.
Pilot input required here. If you're flying straight and level with the flap setting required at 6000 feet (?), what's the average trim setting? (aka... how long is a piece of string).